To handle fluids flowing at high rates and under high pressure, oilfield equipment is typically large. Workers needing to inspect and repair: wellhead valve assemblies, pumping units, separators, tanks, compressors, and the like, are frequently called upon to access areas well above the height of a man. To gain access, many workers carry ladders in their vehicles as part of their tool kit. Ladders are bulky, however, taking up much room that can be devoted to other productive purposes. Furthermore, depending on size and weight, ladders can be difficult and dangerous for a single worker to lift and move. Thus, oilfield workers must often work inefficiently in larger groups than necessary.